This invention relates to footwear and in particular to footwear with embedded orthotic devices.
The outsole design in known sports and leisure activity footwear serves as a flat, semi ridged platform to support and cushion the entire surface of the foot. The manufactures main focus are on cost and utilizing established manufacturing techniques to produce stylized differentiated designs between brands and model lines. The sole design offered in footwear today provides a generalized stationary cushioning bed for a foot's contours in insulating contact against the ground. While cushioning and support are addressed with the midsole inserts for arches and heel support, it is unable to fully and evenly support the full contours on the soles. The inability of footwear to fully support the foot by capturing contours of the soles hinders the outsole's ability to evenly distribute weight of the wearer's body across the entire sole surface. Furthermore, a stationary sole platform is not able to capture the foot's natural biomechanical movements and translate them into compression and directional flex motions onto the footwear. Due part in design and in manufacturing process, current production footwear are made to cushion and support the wearer's foot made by established methods of footwear construction. A new approach of constructing an outsole system to fully capture the foot's natural movements, and benefit a wearer by evenly supported the weight of the entire foot, is needed.
Typical constructions in most footwear outsole consists of three main components: 1) a semi flexible molded bottom outsole using urethane rubber to provide traction and protection of the foot; 2) a single density polyurethane foam added to the outsole to provide additional cushioning and support needs; and 3) a midsole or liner is then added on top of outsole to provide additional contoured cushioning against the flat foot bed surface. Flat layers of midsole and outsole are often used due to ease of manufacturing process as they can be die cut from flat sheet materials. However, the soles of feet have unique contours and structural load bearing zones like the heel and the forefoot. The cushioning needs of the foot may requires localized load bearing zones to provide a more adequate cushioning and support throughout different regions of the foot. The combination of molded outsole, midsole and liner can make the overall footwear feel stiff, rigid and insufficiently insulate the wearer's foot from the ground surface. Fused with multi layered upper construction adds to the overall footwear rigidity with boot like hardness.
Construction of a flat, rigid outsole and its inability to emulate the bottom contours of the foot hinders a foot's natural biomechanical movement in a gait cycle. Some midsole currently on the market are molded with mid foot arch contours to assist in supporting the mid foot, but they do not fully capture the mid foot arch surfaces. The midsole used only provide minimal medial arch support by vertical downward compression of the foam material used. While the full directional flex motions as the foot pronates and supenates during a gait cycle are not supported by the midsole insert. As weight is being distributed onto the foot, the pronatory and supenatory effects change the shapes of the foot to absorb the load. This range of motion is cushioned by midsole foam but not captured or enhanced by the footwear.
Over time the midsole and outsole foam material breaks down as (Ethylene Vinyl Acetate) EVA deteriorates and looses its rebound elasticity quickly. Foot pain and discomfort soon ensues. The result of incorrect and inadequately support from the footwear attributed by the flat and rigid outsole design creates many problems for the foot. The lack of mid foot arches support are a common problem causing pain and discomfort for the wearer. The lack of proper mid foot arch support may lead to over pronation as the cause of heel pain known as Plantar Fasciitis. Calluses, and Bunion are some of the other symptoms caused by over pronation. Without proper support of the mid foot, the heel and fore foot are tasked to bare the entire weight. This also attributes to the causes of heel, mid foot and forefoot discomfort and pain. As the soles of the footwear deteriorates over time and use, the wearer may find their foot with a shorter threshold to withstand pain and discomfort from the footwear.
As incorrect and inadequately support in the footwear causes pain and discomfort. Wearers seek relief from discomfort, and foot pain by purchasing foam or soft silicone gel insole inserts to provide additional cushioning for their feet. Using the inserts can create other problems as the original footwear is not designed for use with the unique shapes and contoured thickness of the inserts. This causes fit and comfort issues with the upper while raising the heel height on the lower outsole. In some cases, custom formed orthotics of ridged thermoplastics or composite inserts with custom formed mid foot arches are used for wearer's with chronic foot pains. Much like placing a brand new house on an existing foundation not designed to support the new house, the orthotic insert device is placed on top of the outsole while the bottom surfaces are not being fully supported. The orthotic inserts can not perform properly due to the lack of stable regionalized support needed to directly engage the ground plane through the outsole. Overly cushioning and supporting the foot with added insert devices may not address the need for footwear to flex and move with the natural biomechanical moments of the foot particularly in the mid foot arch region. While artificially raising the heel height can create instability for the heel to lose balance and slip off the inserts causing twist ankle injuries. A system of support is need which fully supports the regional load bearing zones of the foot.
The current production footwear outsole only serves as a flat stationary platform for the foot to rest on. A new system of flexible support is needed to cooperate the movements of the foot. This requires a completely redesigned sole system is needed to achieve comfort, support and enable the soles to move and flex with the foot. The ability for a footwear to flex with the biomechanical motions of the foot in a gait cycle requires the motions of pronation and supenation to be identified and quantified in order to translate into applicable flexing movements of the outsole system.
Human mobility consists of bi pedal movements defined as a gait cycle. During the gait cycle, the heel strikes the ground first, then the mid foot and forefoot rolls forward to establish contact to the ground. Weight then is shifted over the foot as the foot goes though a tri lateral motion called pronation. The movement of pronation and supenation consists of motions in three planes, the saginal plane, the frontal plane, and the horizontal plane. In the saginal plane, the fore foot rotates up as it pronates in dorsiflexion and down as it supenates in plantarflexion. In the frontal plane the foot rotates out as it pronates in inversion and rotates in as it supenates in eversion. In the horizontal plane, the foot pivots out as it pronates in adduction and pivots in as it supenates in abduction. Pronation can be seen as a spring like compression of the foot to absorb the weight of the body. While supenation is the rebound of the foot as it return to its original, unloaded state.
Different parts of the foot have unique cushioning and support needs driven by the bone structures and biomechanical motion of the foot. The rear of the foot, known as the heel, contains the Calcaneus bone structure which serves as the main load bearing base for the foot when in motion or at rest. The heel also provides the initial landing strike to the ground during a gait cycle as part of the bi pedal movement. As the heel strikes the ground the heels may be subjected to the entire weight of the body. During running, jumping and other athletic sports activities, the heel strike may far exceed one's own body weight. Thus a denser cradle made to reflect the contours of the heel can better protect and distribute energy more evenly across the heel zone.
The mid foot consists of a key stone like structure with the Navicular, Cuboids, and Cuneiform bones. It also houses the Tarsometatarsal joint which serves as a connection to the first though fifth Metatarsal bones. Mid foot is also know as a medial and lateral arches of the foot. The mid foot joint structure serves as a compressible arch to allow flex as part of the suspension system of the foot to absorb the weight of the body. Due to the biomechanical nature of feet, support for the mid foot in flex of medial and lateral arch is a much needed element to incorporate into the outsole design.
The forefoot is located at the ends of the metatarsal bone as it connects to the phalanges, also known as toes. At the joints of the phalanges and the first Metatarsal joint lies the Sesamoid bone. The Sesamoid bone with the ends of the first Metatarsal, are also known as the ball of the foot. The forefoot also expands and pivots outward in adduction as part of pronatory motions. This motion can be attributed as a byproduct of compression in the mid foot. Thus, a need exists for an orthotics sole system which allows for this movement as part of flexing motion. The forefoot further serves as another load bearing zone, as the weight of the body is mainly distributed onto the fore foot and the foot's heel region. The forefoot is also responsible for propulsion as the foot rolls forward to begin the pushing off the stage of the gait cycle.
In the footwear upper design, thong type sandals are among the most popular styles on the market. This popularity is due to comfort and the simplistic nature of its design. While it is easy to slip in and out of the thong style sandal, the length of the straps are not adjustable. Due to lose fitting straps, the wearer often has to consciously maneuver their toes and forefoot to keep the sandals on and in place as the heel may shift from left to right. The problem is compounded as straps and sole material gets worn and stretched out. To achieve a secured and proper fit for the foot, a device is needed to easily adjust the length of the straps.
The toe loop in sandals are typically made with thin and flexible woven materials. Located between the toes or phalanges of the first and second metatarsal, the loops are often the source of discomfort. It can be difficult to keep the forefoot in position with the footwear as loose materials are used to connect the straps to the outsole which allows the forefoot to slide from side. A semi ridged toe post device is needed to keep the foot in position with the outsole.
Most common footwear upper construction utilizes lacing to achieve proper fit to footwear uppers as methods of securing the foot. Since most footwear upper construction utilizes non stretchable materials, lacing and/or elastic material is used to achieve proper fit and secure the footwear to the foot. The foot is first strapped in, then presses down into the sole as lacing is tightened over to secure the foot. This method of adjustment no doubt creates uneven pressure points along the entire fore and mid foot in static or in motion. It may also cause binding on the upper because as the forefoot bends, it creates high tension areas as the upper is unable to stretch and accommodate the movement of the foot in pushing off stage of the gait cycle. Due to unique foot shapes, a better way of securing the foot to the footwear is needed to address fit, comfort, and more evenly distribute pressure across the foot.
Sandals at times need to be stored vertically as they are often washed and dried. At the beach they are carried by hand as wearer walks in sand and in surf. A better way of carrying and storing the sandals with a feature to combine both left and right foot when it's not in use is needed.